- International Commission on Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes referred to by the unofficial "International Stratigraphic Commission" is a daughter or major
subcommitteegrade scientific daughter organization that concerns itself with stratigraphy, geological, and geochronological matters on a global scale.
It is an subordinate body of the
International Union of Geological Sciences—of which it is the largest scientific body within the organisation—and of which, it is essentially a permanent working subcommittee that meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or membership of the whole.
One of its main aims, a project begun in
1974, is to establish a multidisciplinary standard and global geologic time scalethat will be thereafter ease paleontogical and geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Points (GSSP)s within the fossil record. (i.e section of the rock record as of a core sample section or accessible exposed strata, which when a core sample are usually "trayed" in long pieces, also called "sections" about a meterin length.)
Additionally the ICS defines an alternative type of benchmark and criteria called
Global Standard Stratigraphic Ages (GSSAs) where the characteristics and dating criteria set solely by physical sciencesmethods (such as magnetic alignment sequences, radiological criteria, etcetera.) as well as encouraging an international and open debate amongst Earth scientists in the many scientists in the paleontology, geology, geobiologyand chronostratigraphyfields, among others.
The International Commission on Stratigraphy has spawned numerous
subcommitteelevel organizations organized and mobilized on a local country-wide or regional basis that are the true working committees of the IUGS, and these do the field work, basis comparisons in conference or co-ordination research committeemeetings of local or wide-scale scope.
The ICS publishes various reports and findings as well as revised references periodically, summarized in the [http://www.stratigraphy.org /cheu.pdf International Stratigraphic Chart] , a combined "working proposal" and "guideline-to-date" released after the last ICS deliberations prior to the upcoming (next) meeting of the IUGS (PDF file, updated January 2008, compare with the [ ICS-I.S. Chart of 2004] ). Until the IUGS accepts the recommendations, they are unofficial since the IUGS parent approves or dismisses the individual deliberation reports of the ICS, which are presented as recommendations, and span dating and strata selection criteria, and related issues including nomenclatures. In "
de facto" everyday matters, the deliberative results reported out of any meetings of the ICS are widely accepted and immediately enter everyday use, except in the rare cases where they result in a strong body of dissenting opinion, which matters are resolved before the full IUGS.
One such controversy arose this past year when the ICS deliberated and decided the
PliocenegSeries of the current but unofficially named QuaternarygPeriod should be shifted into the NeogenegSystem and period. The term Quaternary has yet to be officially adopted by the IUGS, but has widespread support as acceptable nomenclature for the current geologic period beginning at the GSSPaccepted at 5,332,000 years ago at the transition between the Messinian age to the Zanclean(3.6 mya) gAge. The ICS voted, perhaps because the time units span human paleoarchelogical strata, to begin the Quaternary at the end GSSP of the Piacenzian age (2.588 mya) or possibly the end of the Gelasian(1.806 mya), any of which are in a different gEpoch.
Notes, links and references
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